Translucent enamel.



sodium, five to nine parts.

UNITED STATES,

PATENT OFFICE.

LONDON,

ENGLAND.

TRANSLUCENT ENAM EL.

SPECIFICATION forming part Of Letters Patent No. 634,117, dated October3, 1899 Application filed December 29, 1897. Renewed September 6, 1899.Serial No. 729,668. (Specimens) To all whom it may concern.-

Be it known that we, WILLIAM LUTWYOHE and WILLIAM BARBER LUTWYOHE,subjects of the Queen of England, residing at 19 Goulton road, LowerClapton, London, N. E. England, have invented a new and usefulComposition of Matter to be Used in the Manufacture of- TranslucentEnamel, (for which we have obtained a patent in Great Britain, No.5,934,

dated March 21, 1895,) of which the following is a specification.

For white enamel we employ the following: minium, one hundred and fiftyto two hundred parts; boracic acid, eighty to one hun dred parts; zincoxid, fifty to eighty parts; stannic acid, thirty to, forty parts;powdered flint, fifty to sixty parts; feldspar, five to ten I parts;finer-spar, five to ten parts; pearlash, two to five parts; the peculiarpreparation of carbonate of soda known as sel de St. Gobain, twenty tothirty parts; bone-ash, five to ten parts; calcined borax, eight totwelve parts; niter, two to five parts; chlorid of These must beniiiredand melted and then pounded in a mortar, after which the wholemass is groun to a fine powder.

For coloring the enamel we use for blue the compound hydrate of aluminaand hydrated protoxid of cobalt; for black, the preparation of oxid ofmanganese known as oxid noir de Dubois; for yellow, oxid of antimony oroxid of uranium; for pink, carmine.

The proportions of the coloring matters vary according to the tintrequired.

The whole is mixed, melted, and powdered, as above described.

The enamel is applied to glass or other ma terial in the form of apaste, which is made by mixing the fine enamel-powder with water andapplying the same to the surface of the glass or other material by meansof a spatula.

It is then placed in a kiln and fired till the Dubois, oxid of antimony,oxid of uranium,

and car-mine, in the proportions and for the purposes specified. I

In witness whereof we hereunto set our hands in presence of twowitnesses.

WILLIAM LUI'WYCHE. WILLIAM BARBER LUTWYCIIE.

Witnesses:

DANIEL BRIDEGROOM, WILLIAM HENRY. MuNNs.

